Germany (code DEU) was created 3 October 1990 by the accession of the Democratic Republic of Germany (code DDR) to the then Federal Republic of Germany (code DEW).
DEU...Direct source
The national sources underpining the OECD data are:
Germany (code DEU) was created 3 October 1990 by the accession of the Democratic Republic of Germany (code DDR) to the then Federal Republic of Germany (code DEW).